Muscles of the Leg and Foot

The peroneus tertius resembles that of the ox, but its tendon is not perforated by that of the tibialis anterior, and ends on the inner (second) large metatarsal bone, detaching a strong branch to the first and second tarsal bones.

The tibialis anterior arises on the tibial crest. Its tendon passes over the hock along the inner border of the tendon of the peroneus tertius (both being bound down by an annular ligament), and is inserted into the inner (second) metatarsal and first tarsal bones.

The peroneus longus lies partly on the outer surface of the peroneus tertius. Its tendon crosses those of the lateral extensor, passes along a groove on the plantar surface of the fourth tarsal bone, and ends on the first tarsal and second metatarsal bones.

The anterior or long digital extensor arises with the peroneus tertius and is largely covered by it and the peroneus longus. It divides into three parts. The tendon of the inner division (M. extensor digiti tertii) ends on the inner chief (third) digit; that of the middle division by two branches on the principal digits; and that of the outer division by three branches on the second, fourth, and fifth digits.

The lateral digital extensor divides into proper extensors of the fourth and fifth digits (Extensores digiti quarti et quinti).

The extensor hallucis longus arises on the fibula and ends on the inner small (second) digit.

The extensor digitalis brevis is well developed and consists of three parts. The inner and outer tendons end on the first phalanges of the chief digits, the middle one joins the common extensor tendon of the same.

The gastrocnemius presents nothing special.

The soleus is wide, and is partly blended with the external head of the gastrocnemius.

The superficial digital flexor has a large belly. Its tendon ends on the two chief digits, and is also connected with the ligaments of the accessory digits.

The inner head of the deep digital flexor (flexor digitalis longus) is relatively small. The common tendon ends as in the thoracic limb.

The popliteus presents no special features.

The plantar muscles resemble their homologues of the fore limb, except that the adductors of the accessory digits and the lumbricales are absent.